mdw@git.distorted.org.uk Git - disorder/blob - lib/speaker-protocol.h

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2005, 2007, 2008, 2013 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/speaker-protocol.h
  19  * @brief Speaker/server protocol support
  20  *
  21  * This file defines the protocol by which the main server and the speaker
  22  * process communicate.
  23  */
  24
  25 #ifndef SPEAKER_PROTOCOL_H
  26 #define SPEAKER_PROTOCOL_H
  27
  28 #include "byte-order.h"
  29 #include <netinet/in.h>
  30
  31 /** @brief A message from the main server to the speaker, or vica versa */
  32 struct speaker_message {
  33   /** @brief Message type
  34    *
  35    * Messages from the main server:
  36    * - @ref SM_PLAY
  37    * - @ref SM_PAUSE
  38    * - @ref SM_RESUME
  39    * - @ref SM_CANCEL
  40    * - @ref SM_RELOAD
  41    * - @ref SM_RTP_REQUEST
  42    * - @ref SM_RTP_CANCEL
  43    *
  44    * Messages from the speaker:
  45    * - @ref SM_PAUSED
  46    * - @ref SM_FINISHED
  47    * - @ref SM_PLAYING
  48    * - @ref SM_UNKNOWN
  49    * - @ref SM_ARRIVED
  50    */
  51   int type;
  52
  53   /** @brief Message-specific data */
  54   long data;
  55
  56   union {
  57     /** @brief Track ID (including 0 terminator) */
  58     char id[24];                          /* ID including terminator */
  59
  60     /** @brief An IP address (for @ref SM_RTP_REQUEST and @ref SM_RTP_CANCEL) */
  61     struct sockaddr_storage address;
  62   } u;
  63 };
  64
  65 /* messages from the main DisOrder server */
  66
  67 /** @brief Play track @c id
  68  *
  69  * The track must already have been prepared.
  70  */
  71 #define SM_PLAY 1
  72
  73 /** @brief Pause current track */
  74 #define SM_PAUSE 2
  75
  76 /** @brief Resume current track */
  77 #define SM_RESUME 3
  78
  79 /** @brief Cancel track @c id */
  80 #define SM_CANCEL 4
  81
  82 /** @brief Reload configuration */
  83 #define SM_RELOAD 5
  84
  85 /** @brief Reload configuration */
  86 #define SM_RTP_REQUEST 6
  87
  88 /** @brief Reload configuration */
  89 #define SM_RTP_CANCEL 7
  90
  91 /* messages from the speaker */
  92 /** @brief Paused track @c id, @c data seconds in
  93  *
  94  * There is no @c SM_RESUMED, instead @ref SM_PLAYING is sent after the track
  95  * starts playing again.
  96  */
  97 #define SM_PAUSED 128
  98
  99 /** @brief Finished playing track @c id */
 100 #define SM_FINISHED 129
 101
 102 /** @brief Never heard of track @c id */
 103 #define SM_UNKNOWN 130
 104
 105 /** @brief Currently track @c id, @c data seconds in
 106  *
 107  * This is sent from time to time while a track is playing.
 108  */
 109 #define SM_PLAYING 131
 110
 111 /** @brief Speaker process is ready
 112  *
 113  * This is sent once at startup when the speaker has finished its
 114  * initialization. */
 115 #define SM_READY 132
 116
 117 /** @brief Cancelled track @c id which wasn't playing */
 118 #define SM_STILLBORN 133
 119
 120 /** @brief A connection for track @c id arrived */
 121 #define SM_ARRIVED 134
 122
 123 void speaker_send(int fd, const struct speaker_message *sm);
 124 /* Send a message. */
 125
 126 int speaker_recv(int fd, struct speaker_message *sm);
 127 /* Receive a message.  Return 0 on EOF, +ve if a message is read, -1 on EAGAIN,
 128  * terminates on any other error. */
 129
 130 /** @brief One chunk in a stream */
 131 struct stream_header {
 132   /** @brief Number of bytes */
 133   uint32_t nbytes;
 134
 135   /** @brief Frames per second */
 136   uint32_t rate;
 137
 138   /** @brief Samples per frames */
 139   uint8_t channels;
 140
 141   /** @brief Bits per sample */
 142   uint8_t bits;
 143
 144   /** @brief Endianness */
 145   uint8_t endian;
 146 } attribute((packed));
 147
 148 static inline int formats_equal(const struct stream_header *a,
 149                                 const struct stream_header *b) {
 150   return (a->rate == b->rate
 151           && a->channels == b->channels
 152           && a->bits == b->bits
 153           && a->endian == b->endian);
 154 }
 155
 156 #endif /* SPEAKER_PROTOCOL_H */
 157
 158 /*
 159 Local Variables:
 160 c-basic-offset:2
 161 comment-column:40
 162 fill-column:79
 163 indent-tabs-mode:nil
 164 End:
 165 */